@article{oai:iwate-u.repo.nii.ac.jp:00015869,
 author = {國崎, 貴嗣 and 白旗, 学 and 松木, 佐和子},
 issue = {4},
 journal = {日本森林学会誌, Journal of the Japanese Forest Society},
 month = {Aug},
 note = {最近（2011年または2012年）に間伐された過密壮齢林2林分を対象に，本数率30％前後の強度が中庸な下層間伐が樹冠長の7年間の変化および4年間の胸高直径成長に及ぼす影響を調べた。いずれの間伐林でも平均樹冠長は時間とともに増加した。間伐林における樹高の成長速度は0.2 m/年前後であるのに対し，生枝下高の上昇速度はほぼ0.0 m/年であった。間伐林の平均胸高直径成長量は，放置林のそれより有意に高かった。また，期首胸高直径と胸高直径成長量の関係では，期首胸高直径が大きな立木ほど間伐林と放置林の胸高直径成長量の差が大きくなった。本研究は，中庸な下層間伐によって，過密壮齢林における樹冠底部の生枝の枯れ上がりが停止した事例を報告した。ただし，樹冠競合で相対的に劣勢な立木ほど，胸高直径成長促進の効果が低くなると考えられる。, The effects of moderate low thinning of around 30％ in number ratio on changes in crown length for seven years and DBH growth for four years were investigated in overcrowded mature plantations of Sugi (Cryptomeria japonica D. Don). Mean crown length increased with time in the thinned stands. In the thinned stands, mean height increment was approximately 0.2 m/year, while the rising rate of crown base was nearly 0.0 m/year. Mean DBH increment in the thinned stands was significantly higher than that in the unthinned stand. As for the relationship between initial DBH and DBH increment, the greater the initial DBH, the greater the difference in the increment between the thinned stands and the unthinned stand. There are cases in which the rise of crown base in overcrowded mature stand can be stopped even by moderate low thinning. However, thinning effect on DBH growth would decrease, as the trees which are comparatively suppressed among inter-tree competition.},
 pages = {223--228},
 title = {過密なスギ壮齢人工林における間伐効果：樹冠長と胸高直径成長量に基づく分析},
 volume = {104},
 year = {2022}
}